Yeah i also think about that "they only used by criminals". People around me thinks the same because they think that bitcoin is designed to use in deep web to use for illegal activities but they're wrong .
Even media will keep on showing news about the bad side of bitcoin, I see it's not a big deal after all.
If people really want to know more about bitcoin, they will take time to learn what bitcoin really is. And every bad news is just a shit to them because they are the one who will found out if bitcoin is bad or not.
Media has never shown their support towards bitcoin and that is the reason many people hesitate in investing into bitcoin as they have more faith in news and media.